The report aims to support dialogue among tax officials and highlight opportunities to improve tax system design and administration.
The OECD has published a report titled “Tax Administration 2025: Comparative Information on OECD and other Advanced and Emerging Economies,” on 17 November 2025, providing internationally comparative data on tax systems and administration across 58 jurisdictions. The report aims to support dialogue among tax officials and highlight opportunities to improve tax system design and administration.
The 2025 report, covering performance data up to the 2023 fiscal year, provides a decade-long perspective on tax administration and the increasing impact of artificial intelligence (AI). The results show that in 2023, 69% of surveyed tax authorities were already using AI, while 24% planned to implement it.
Tax Administration 2025 is the 13th edition of the OECD Centre for Tax Policy and Administration’s comparative information series. First published in 2004, the primary purpose of the Tax Administration Series (TAS) is to share information that will facilitate analysis and dialogue on the design and administration of tax systems.
This edition of the TAS provides internationally comparative data on aspects of tax systems and their administration in 58 advanced and emerging economies. While the publication traditionally put its emphasis on performance-related data and ratios for the latest available fiscal year, in this case 2023, a key focus of this edition is a 10-year perspective on the evolution of tax administration.
The publication presents the results of the International Survey on Revenue Administration (ISORA). To provide the longer-term perspective, it compares the latest ISORA data with the 2014 data collected through the very first ISORA survey.
The ISORA survey is a multi-organisation survey to collect information and data on tax administration. It is governed by five partner organisations: the Asian Development Bank (ADB), the Inter-American Center of Tax Administrations (CIAT), the International Monetary Fund (IMF), the Intra-European Organisation of Tax Administrations (IOTA) and the OECD.
To provide further insight into the ISORA data in certain places, TAS 2025 also uses data from the Inventory of Tax Technology Initiatives (ITTI). ITTI is an online database containing information on technology tools and digitalisation solutions implemented by tax administrations across the globe. It has been developed by the OECD’s Forum on Tax Administration (FTA) together with nine key partner organisations. This report was approved by the Committee on Fiscal Affairs on 29 October 2025 and prepared for publication by the OECD Secretariat.
Introduction
In 2017, the seventh edition of the TAS described the changing face of tax administration noting how new technologies, analytical tools and a significant increase in the data tax administrations had access to was allowing them to rethink their operational models, providing new opportunities to improve services, enhance compliance and reduce burdens.
The embedding of technology into tax administration has continued at pace since then, including the rise of AI, and, in 2020, the OECD formulated its vision of a digitally transformed tax administration, referred to as Tax Administration 3.0.
This future of tax administration has inspired the strategic plans of many tax administrations, and some are well underway with their digital transformation.
To obtain insights as to how tax administration has evolved over the past years, this edition of the TAS compares in several instances 2023 fiscal year data collected through the 2024 ISORA survey, with the historical 2014 data. While this 10-year perspective, comparing ISORA data for fiscal years 2014 and 2023, needs to be considered with caution due to changing circumstances of tax administration, such as new responsibilities, it nevertheless allows high level insights as to the evolution of tax administration.
As previously, alongside the ISORA data, the tax administrations covered in this edition of the TAS were also invited to provide examples of innovative practices that they are undertaking to help achieve their objectives. They have provided a rich source of over 80 examples, covering a wide range of topics.
While these examples do not form a basis for comparison across tax administrations in the same way as the ISORA data points can in some circumstances, they do add more colour to the data and give pointers to the strategic direction of travel of tax administrations globally, as is evident by the large number of AI-related examples provided. Furthermore, this edition of the TAS continues to use information from the ITTI database.
ITTI collects data on the digital transformation and digitalisation work of tax administrations from across the globe, and this rich source of data can provide further insight into the developments taking place in tax administration, facilitating mutual learning and collaboration.
